The expression of calpain 1 and calpain 2 in spermatogenic cells and spermatozoa of the mouse
The expression of calpain 1 and calpain 2 in spermatogenic cells and spermatozoa of the mouse
复制标题
DOI：
10.1530/rep.1.00255
复制
发表时间：
2005-04-01
期刊：
影响因子：
3.8
通讯作者：
Shalgi, R
中科院分区：
文献类型：
--
作者：
Ben-Aharon, I;Brown, PR;Shalgi, R
有一些证据表明，Ca 2+参与精子发育和功能过程。钙依赖性蛋白，如钙调素，在哺乳动物精子发生过程中表达，进一步表明Ca 2+参与其调节。然而，Ca 2+在精子发生中的确切作用仍有待阐明。钙蛋白酶是钙离子依赖性半胱氨酸蛋白酶家族，其成员普遍表达或以组织特异性方式表达。钙蛋白酶已被证明介导特异性钙依赖性过程，包括细胞融合、有丝分裂和减数分裂。我们在此通过RT-PCR和Western印迹分析，在RNA和蛋白质水平上跟踪了钙蛋白酶的普遍存在的异构体1和2在整个精子发生过程中的表达模式。RNA和蛋白质的研究表明，这些异构体在所有的生精细胞中表达。钙蛋白酶1在进入减数分裂期的精母细胞中表达水平略高。这两种钙蛋白酶亚型也在小鼠精子中表达，并定位于顶体帽。诱导获能精子进行顶体反应的存在下，选择性钙蛋白酶抑制剂显着降低顶体反应率在剂量依赖性的方式。因此，钙蛋白酶，一个多能性蛋白酶与众多的底物，可以作为一个以上的途径在精子发生的复杂过程中的效应，并在受精前的事件，如顶体反应。
There is some evidence suggesting that Ca2+ is involved in processes that occur during the development and function of spermatozoa. Calcium-dependent proteins, such as calmodulin, are expressed during mammalian spermatogenesis further suggesting that Ca2+ takes part in its regulation. However, the precise roles of Ca2+ in spermatogenesis remain to be elucidated. Calpains are a family of Ca2+-dependent cysteine proteases whose members are expressed ubiquitously or in a tissue-specific manner. Calpain has been demonstrated to mediate specific Ca2+-dependent processes including cell fusion, mitosis and meiosis. We herein followed the expression pattern of calpain's ubiquitous isoforms, 1 and 2, throughout spermatogenesis at the RNA and protein levels by RT-PCR and Western blotting analysis. Both RNA and protein studies revealed that these isoforms are expressed in all spermatogenic cells. The expression of calpain 1 levels is slightly higher in spermatocytes entering the meiotic phase. Both calpain isoforms are also expressed in mouse spermatozoa and are localized to the acrosomal cap. Inducing capacitated spermatozoa to undergo the acrosome reaction in the presence of a selective calpain inhibitor significantly reduced the acrosome reaction rate in a dose-dependent manner. Thus, calpain, a pluripotential protease with numerous substrates, may serve as an effector in more than one pathway in the complex process of spermatogenesis and in the events preceding fertilization, such as the acrosome reaction.